you know they used to test peoples blood when they got married to see if they were related or not, but they have not done that for a very long time so there are a lot of people who are Married and do or don't know that they are related, then most them have had children who also married a distant cousin, there is probably a 0.1 percent chance that we are all related.
I would have my DNA tested if got Married, and find out if I was related to my spouse or not. When you are in love you probably wouldn't care though that is how love works.